One of the most unfortunate side effects of the identification of the Boston Marathon bombers was that they were tagged as immigrants. According to their own uncle, they were disaffected “losers” who couldn’t make it in America.

This fed into the myth that most immigrants to this country are “deadbeats,” rather than people looking for a chance to succeed in America.

Teddy Kennedy’s 1965 immigration bill dramatically widened the number of immigrants America admits from around the world. America is a sanctuary for people targeted in their own countries for simply asking for basic human rights, things we too often take for granted like the right to vote and equality under the law.

We welcome immigrants from countries ranging from Palestine, Bosnia and Pakistan to Ukraine and Nigeria.

The earliest U.S. restrictions on immigration sought to admit only people from Canada or Western Europe. There are some politicians and commentators today who would like to go back to that formula, to get a “better class” of immigrants into this country.

So let us pause and consider the ways in which America would be different if these restrictive immigration policies were in place today. Which country would have been enriched by: An Wang (Wang Labs), Amar Bose (Bose Corporation), Jerry Yang (Yahoo), Vinod Khosla (Sun Microsystems), Steve Chen/Jawed Karim (YouTube), Sergey Brin (Google), S.Chandrashekar and Har Gobind Khorana (Nobel Laureates in astrophysics and biochemistry, respectively)?

Thousands of South and East Asian immigrants have enriched the American economy. Their brainpower and creative hard work have made Silicon Valley synonymous with cutting edge developments in high tech and the envy of the world. Asian American immigrants and their sons and daughters own 1.5 million US businesses with an annual payroll of more than $100 billion.

The list of successful immigrants from non-European countries is legion, and it is to state more than the obvious to speak of their significant and manifold contributions to almost any field of endeavor in the United States. Given the opportunities that this nation affords, they have “made it in America.”

It is salutary to remind ourselves that America is a nation of immigrants, only that some got here earlier than others. Yes, recently arrived immigrants sometimes commit violence and criminal acts, usually less catastrophic acts than the Boston bombings. There are failures as well — just as they are, and were, by earlier waves of immigrants.

Not all “losers” in America are recent arrivals, just as not all multi-generation Americans are losers.” The larger question is: at what point do immigrants from “Third World” countries cease to be immigrants and become “real Americans?” How many generations have to pass before country of origin is erased in defining nationality?

In this country, we are tied together by the democratic ideals laid out in our founding documents, not by ethnic identity. By proclaiming, in 1776, that “all men are created equal,” we became a beacon of light to the world and attracted some of the worlds best thinkers and inventors and business entrepreneurs. That is what we should be celebrating as the 237th anniversary of this Nation of Immigrants approaches.

Seetha Srinivasan is Director Emerita University Press of Mississippi.